Condensed Consolidated Statements of Earnings and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Net sales	$ 260.5	$ 233.9	$ 736.4	$ 679.3
Cost of goods sold	162.6	143.1	485.0	425.0
Gross profit	97.9	90.8	251.4	254.3
Selling, general and administrative expenses	35.3	30.8	113.7	105.8
Equity earnings from joint venture	(18.7)	(13.9)	(59.2)	(51.9)
Operating income	81.3	73.9	196.9	200.4
Interest expense	9.9	8.8	28.9	26.6
Other non-operating (income) expense, net	(9.2)	12.3	(27.3)	(4.9)
Earnings from continuing operations before income taxes	80.6	52.8	195.3	178.7
Income tax expense	16.4	15.5	42.3	62.2
Earnings from continuing operations	64.2	37.3	153.0	116.5
Net earnings (loss) from discontinued operations, net of tax (benefit) expense of ($0.5), $2.2, $1.2 and $8.7	5.0	6.2	14.4	(0.7)
Gain (loss) from disposal of discontinued business, net of tax (benefit) of ($4.6), ($5.9), ($4.9) and ($5.4)	7.0	5.9	(16.1)	5.3
Net gain (loss) from discontinued operations	12.0	12.1	(1.7)	4.6
Net earnings	76.2	49.4	151.3	121.1
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(7.0)	7.0	(21.9)	20.9
Derivative gain (loss), net	(0.5)	(0.3)	5.3	(2.0)
Pension and postretirement adjustments	2.7	14.3	7.6	18.8
Total other comprehensive (loss) income	(4.8)	21.0	(9.0)	37.7
Total comprehensive income	$ 71.4	$ 70.4	$ 142.3	$ 158.8
Earnings per share of common stock, continuing operations:
Basic	$ 1.26	$ 0.70	$ 2.94	$ 2.17
Diluted	1.23	0.69	2.89	2.16
Earnings (loss) per share of common stock, discontinued operations:
Basic	0.24	0.23	(0.03)	0.09
Diluted	0.23	0.23	(0.03)	0.08
Net earnings per share of common stock:
Basic	1.50	0.93	2.91	2.26
Diluted	$ 1.46	$ 0.92	$ 2.86	$ 2.24
Average number of common shares outstanding:
Basic	50.7	53.0	51.9	53.5
Diluted	51.9	53.5	52.8	53.9